#!/usr/bin/python

##
## func command line interface & client lib
##
## Copyright 2007, Red Hat, Inc
## Michael DeHaan <mdehaan@redhat.com>
## +AUTHORS
## 
## This software may be freely redistributed under the terms of the GNU
## general public license.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
##

import optparse
import sys
import xmlrpclib
import traceback
import glob
import os


import sslclient

# ===================================
# defaults
# TO DO: some of this may want to come from config later

DEFAULT_PORT = 51234
CERT_PATH = "/var/lib/func/certmaster/certs"

FUNC_USAGE = "Usage: %s [ --help ] [ --verbose ] target.example.org module method arg1 [...]"

# ===================================

class CommandAutomagic():
   """
   This allows a client object to act as if it were one machine, when in 
   reality it represents many.
   """

   def __init__(self, clientref, base):
       self.base = base
       self.clientref = clientref

   def __getattr__(self,name):
       base2 = self.base[:]
       base2.append(name)
       return CommandAutomagic(self.clientref, base2)

   def __call__(self, *args):
       if not self.base:
           raise AttributeError("something wrong here")
       if len(self.base) < 2:
           raise AttributeError("no method called: %s" % ".".join(self.base))
       module = self.base[0]
       method = ".".join(self.base[1:])
       return self.clientref.run(module,method,args)

# ===================================

class Client():

   def __init__(self, server_spec, port=DEFAULT_PORT, verbose=False, silent=False, noglobs=False):
       """
       Constructor.  
       @server_spec -- something like "*.example.org" or "foosball"
       @port -- is the port where all funcd processes should be contacted
       @verbose -- whether to print unneccessary things
       @silent -- whether to print anything
       @noglobs -- specifies server_spec is not a glob, and run should return single values
       """

       self.server_spec = server_spec
       self.port        = port
       self.verbose     = verbose
       self.silent      = silent
       self.noglobs     = noglobs
       self.servers     = self.expand_servers(self.server_spec)

   # ----------------------------------------------- 

   def expand_servers(self,spec):
       """
       Given a regex/blob of servers, expand to a list
       of server ids.
       """

       if self.noglobs:
           return [ "https://%s:%s" % (spec, self.port) ] 

       all_hosts = []
       all_certs = []
       seperate_gloobs = spec.split(";")
       for each_gloob in seperate_gloobs:
           actual_gloob = "%s/%s.pem" % (CERT_PATH, each_gloob)
           certs = glob.glob(actual_gloob)
           for cert in certs:
               all_certs.append(cert)
               host = cert.replace(CERT_PATH,"")[1:-4]
               all_hosts.append(host)

       # debug only:
       # print all_hosts
       
       all_urls = []
       for x in all_hosts:
           all_urls.append("https://%s:%s" % (x, self.port))

       if self.verbose and len(all_urls) == 0:
           sys.stderr.write("no hosts matched\n")

       return all_urls

   # -----------------------------------------------

   def __getattr__(self, name):
       """
       This getattr allows manipulation of the object as if it were
       a XMLRPC handle to a single machine, when in reality it is a handle
       to an unspecified number of machines.
   
       So, it enables stuff like this:
   
       Client("*.example.org").yum.install("foo")

       # WARNING: any missing values in Client's source will yield
       # strange errors with this engaged.  Be aware of that.
       """
   
       return CommandAutomagic(self, [name])

   # ----------------------------------------------- 

   def run(self, module, method, args):
       """
       Invoke a remote method on one or more servers.
       Run returns a hash, the keys are server names, the values are the returns.
       The returns may include exception objects.
       If Client() was constructed with noglobs=True, the return is instead just
       a single value, not a hash.
       """

       results = {}

       for server in self.servers:

	   conn = sslclient.FuncServer(server)
           # conn = xmlrpclib.ServerProxy(server)

           if self.verbose:
                sys.stderr.write("on %s running %s %s (%s)\n" % (server, module, method, ",".join(args)))

           # FIXME: support userland command subclassing only if a module
           # is present, otherwise run as follows.  -- MPD

           try:
                # thats some pretty code right there aint it? -akl
                # we can't call "call" on s, since thats a rpc, so
                # we call gettatr around it. 
                meth = "%s.%s" % (module, method)
                retval = getattr(conn, meth)(*args[:])
                if not self.silent:
                    print retval 
           except Exception, e:
                retval = e 
                if not self.silent:
                    sys.stderr.write("remote exception on %s: %s\n" % (server, str(e)))

           if self.noglobs:
               return retval
           else:
               left = server.rfind("/")
               right = server.rfind(":")
               server_name = server[left:right]
               results[server_name] = retval

       return results

   # ----------------------------------------------- 

   def cli_return(self,results):
       """
       As the return code list could return strings and exceptions
       and all sorts of crazy stuff, reduce it down to a simple
       integer return.  It may not be useful but we need one.
       """
       numbers = []
       for x in results.keys():         
           # faults are the most important
           if type(x) == Exception:
               return -911
           # then pay attention to numbers
           if type(x) == int:
               numbers.append(x)

       # if there were no numbers, assume 0
       if len(numbers) == 0:
           return 0

       # if there were numbers, return the highest 
       # (presumably the worst error code
       max = -9999
       for x in numbers:
           if x > max:
               max = x
       return max

# ===================================================================

class FuncCommandLine():

    def __init__(self,myname,args):
        """
        Constructor.  Takes name of program + arguments.
        """
        self.myname       = myname
        self.args         = args
        self.verbose      = 0
        self.server_spec  = None
        self.port         = DEFAULT_PORT

    # ----------------------------------------------- 

    def usage(self):
        """
        Returns usage string for command line users.
        """
        return FUNC_USAGE % self.myname

    # ----------------------------------------------- 

    def run(self):
        """
        Engages the command line.
        """
        
        rc = self.parse_command_line()
        if rc != 0:
           return rc

        return self.run_command()

    # ----------------------------------------------- 

    def parse_command_line(self):
        """
        Parses the command line and loads up all the variables.
        """

        # parse options
        p = optparse.OptionParser()
        p.add_option("-v","--verbose",dest="verbose",action="store_true")
        p.add_option("-p","--port",dest="port",default=DEFAULT_PORT)
        (options, args) = p.parse_args(self.args)

        self.args    = args
        self.verbose = options.verbose
        self.port    = options.port
        # self.help  = options.help 

        # provided for free:
        # 
        #if self.help:
        #    print self.usage()
        #    return -411

        # process arguments
        # a good Klingon program does not have parameters
        # it has arguments, and it always wins them.

        if len(args) < 3:
            print self.usage()
            return -411

        self.server_spec = self.args[0]
        self.module      = self.args[1] 
        self.method      = self.args[2]
        self.method_args = self.args[3:]

        return 0

    # ----------------------------------------------- 

    def run_command(self):
        """
        Runs the actual command.
        """
        client = Client(self.server_spec,port=self.port,verbose=self.verbose)
        results = client.run(self.module, self.method, self.method_args)
    
        # TO DO: add multiplexer support
        # probably as a higher level module.
 
        return client.cli_return(results)

       
# ===================================================================


if __name__ == "__main__":
    # this is what /usr/bin/func will run
    myname, argv = sys.argv[0], sys.argv[1:]
    cli = FuncCommandLine(myname,argv)
    rc = cli.run()
    sys.exit(rc)